// this program is not technically incorrect, but is an obscure enough style to be worth linting #![deny(temporary_cstring_as_ptr)] use std::ffi::CString; macro_rules! mymacro { () => { let s = CString::new("some text").unwrap().as_ptr(); //~^ ERROR getting the inner pointer of a temporary `CString` } } fn main() { let s = CString::new("some text").unwrap().as_ptr(); //~^ ERROR getting the inner pointer of a temporary `CString` mymacro!(); }